Field of the Invention
The present invention relates to a multi-core optical fiber.
Related Background of the Invention
A multi-core optical fiber having a plurality of core portions extending along a central axis of the fiber, in a common cladding portion is expected as an optical transmission line capable of transmitting a large volume of information. Such multi-core optical fiber is required to reduce crosstalk between two neighboring core portions out of the plurality of core portions in the common cladding. With reduction of crosstalk, it becomes feasible to implement transmission of optical signals by use of a longer multi-core optical fiber. As another advantage, the crosstalk reduction allows reduction in core pitch between two neighboring core portions and thus allows a larger number of core portions to be arranged in the common cladding; as a result, it becomes feasible to transmit a much larger volume of information.
Non Patent Document 1 (Tetsuya Hayashi, et al, Optics Express, Vol. 19, No. 17, pp. 16576-16592 (2011)), Non Patent Document 2 (Tetsuya Hayashi, et al, ECOC 2011, Mo.1.LeCervin.3), and Non Patent Document 3 (Tetsuya Hayashi, et al, ECOC 2010, We.8.F.6) describe the reports on relationship between bending of the multi-core optical fiber (macrobend or microbend) and crosstalk. Non Patent Document 1 reports the relationship between bending and crosstalk in the multi-core optical fiber wherein the plurality of core portions in the common cladding have the structure of the same kind. Non Patent Documents 2 and 3 report the relationship between bending and crosstalk in the multi-core optical fiber wherein two neighboring core portions out of the plurality of core portions in the common cladding have respective structures of different kinds.